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A puncture wound is defined as a wound whose depth is greater than its width. Injuries occur when great focal pressure is applied to a sharp object that can then penetrate the skin and deep tissues. Given the force and depth of penetration, puncture wounds are problematic regardless of location and are independently associated with higher incidence of infections and complications compared to other wounds.1,2 Despite a relatively innocuous appearance, puncture wounds carry a significant risk of infection and injury to underlying structures. Puncture wounds caused by high-pressure injection equipment and animal bites and those involving exposure to body fluids have the potential for unique complications.
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With puncture wounds, shear forces between the penetrating object and tissue result in tissue disruption, producing hemorrhage and devitalization of skin and underlying tissues. Inoculation of infectious organisms into the deeper tissues can occur from the penetrating object (with or without leaving behind a foreign body from the object or material that has been pierced)3 or from the skin surface. When the penetrating object is removed, a small skin wound often closes spontaneously, creating a favorable environment for the development of infection. The reported infection rate from plantar puncture wounds is approximately 6% to 11%.4,5 Furthermore, exploration of infected plantar puncture wounds results in foreign material being found in about 25% of patients.6 The rate of infection from puncture wounds associated with dog bites is about 10% to 11%.7
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Most soft tissue infections from puncture wounds are caused by gram-positive organisms. Staphylococcus aureus predominates, followed by other staphylococcal and streptococcal species.4,8-11 Puncture wounds over joints can penetrate the joint capsule and produce septic arthritis. Those that penetrate cartilage, periosteum, and bone can lead to osteomyelitis. Pseudomonas aeruginosa is the most frequent pathogen isolated from plantar puncture wound–related osteomyelitis, particularly when the injury occurs through the rubber sole of an athletic shoe.6,10-12 The source appears to be Pseudomonas that colonizes the foam lining of athletic shoes. Infections from punctures caused by bites have unique pathogens discussed in more detail later in this chapter.
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Difficulty in visualizing and cleaning to the full depth of the injury contributes to the higher risk for infection for puncture wounds compared with other traumatic lacerations. Other host and wound factors are associated with delayed healing and/or infection (Table 46-1).13,14
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